Sørensen et al. (1) report that in Norway, low concentration of 25-hydroxy-vitamin D [25(OH)D] in mothers during pregnancy was associated with an increased risk of type 1 diabetes in the offspring. We would like to point out that one putative confounding factor in their study might have been the intake of n-3 polyunsaturated fatty acids. Childhood n-3 fatty acid intake and status have been linked with the development of pretype 1 diabetes (2), while reasonably powered prospective studies of exposure during pregnancy are …